Although they were a married couple without children, Mio and her husband lived a peaceful life. One day, a young man moved in nearby, and gradually they grew closer. They became so friendly that they even shared meals together. Then one day, unexpectedly, the young man confessed his feelings to Mio, his neighbor and a married woman. Though she valued her loyalty to her husband, Mio found her heart shaken by the young man's passionate advances and masculine strength—and ultimately offered him her anus.